Rechargeable batteries are used in many circumstances for powering user devices. Among these devices are portable telephones, personal digital assistants, and notebooks. Therefore, a charger comprising a voltage generator is provided to recharge the battery. The charger may be realized as an AC/DC converter or as a DC/DC converter, for example for use in a vehicle. In many user devices, the battery may provide power to the user device and simultaneously be charged by the charger. Therefore, it is desirable to provide a power supply with control circuits enabling the voltage generator to serve for simultaneously supplying a load (application) with electric energy as well as for simultaneously charging the battery. Such a battery charging circuit may be realized in a power management integrated circuit of a cellular or portable device, or of any other application using a chargeable battery.